[PATCH 1/2] arm64: kvm: Save/restore MTE registers
From: Steven Price
Date: Mon Jul 13 2020 - 06:01:26 EST
Define the new system registers that MTE introduces and context switch
them. Also hide the MTE feature from the ID register as it isn't
supported in a VM yet.
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 7 +++++++
arch/arm64/include/asm/sysreg.h | 3 ++-
arch/arm64/kvm/hyp/sysreg-sr.c | 14 ++++++++++++++
arch/arm64/kvm/sys_regs.c | 7 +++++++
4 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c3e6fcc664b1..1fc306705193 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -95,6 +95,9 @@ struct kvm_arch {
* supported.
*/
bool return_nisv_io_abort_to_user;
+
+ /* If any VCPU has MTE enabled then all memory must be MTE enabled */
+ bool vcpu_has_mte;
};
#define KVM_NR_MEM_OBJS 40
@@ -122,6 +125,8 @@ enum vcpu_sysreg {
SCTLR_EL1, /* System Control Register */
ACTLR_EL1, /* Auxiliary Control Register */
CPACR_EL1, /* Coprocessor Access Control */
+ RGSR_EL1, /* Random Allocation Tag Seed Register */
+ GCR_EL1, /* Tag Control Register */
ZCR_EL1, /* SVE Control */
TTBR0_EL1, /* Translation Table Base Register 0 */
TTBR1_EL1, /* Translation Table Base Register 1 */
@@ -138,6 +143,8 @@ enum vcpu_sysreg {
TPIDR_EL1, /* Thread ID, Privileged */
AMAIR_EL1, /* Aux Memory Attribute Indirection Register */
CNTKCTL_EL1, /* Timer Control Register (EL1) */
+ TFSRE0_EL1, /* Tag Fault Status Register (EL0) */
+ TFSR_EL1, /* Tag Fault Stauts Register (EL1) */
PAR_EL1, /* Physical Address Register */
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index d6357c4ea015..309dda5dc45c 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -563,7 +563,8 @@
#define SCTLR_ELx_M (BIT(0))
#define SCTLR_ELx_FLAGS (SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C | \
- SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_IESB)
+ SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_IESB | \
+ SCTLR_ELx_ITFSB)
/* SCTLR_EL2 specific flags. */
#define SCTLR_EL2_RES1 ((BIT(4)) | (BIT(5)) | (BIT(11)) | (BIT(16)) | \
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index cc7e957f5b2c..148561412e6f 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -27,6 +27,11 @@
static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
+ if (system_supports_mte()) {
+ ctxt->sys_regs[RGSR_EL1] = read_sysreg_s(SYS_RGSR_EL1);
+ ctxt->sys_regs[GCR_EL1] = read_sysreg_s(SYS_GCR_EL1);
+ ctxt->sys_regs[TFSRE0_EL1] = read_sysreg_s(SYS_TFSRE0_EL1);
+ }
}
static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
@@ -54,6 +59,8 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(SYS_CNTKCTL);
ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
+ if (system_supports_mte())
+ ctxt->sys_regs[TFSR_EL1] = read_sysreg_el1(SYS_TFSR);
ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
ctxt->gp_regs.elr_el1 = read_sysreg_el1(SYS_ELR);
@@ -93,6 +100,11 @@ NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
+ if (system_supports_mte()) {
+ write_sysreg_s(ctxt->sys_regs[RGSR_EL1], SYS_RGSR_EL1);
+ write_sysreg_s(ctxt->sys_regs[GCR_EL1], SYS_GCR_EL1);
+ write_sysreg_s(ctxt->sys_regs[TFSRE0_EL1], SYS_TFSRE0_EL1);
+ }
}
static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
@@ -136,6 +148,8 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], SYS_CNTKCTL);
write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
+ if (system_supports_mte())
+ write_sysreg_el1(ctxt->sys_regs[TFSR_EL1], SYS_TFSR);
if (!has_vhe() &&
cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT) &&
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index baf5ce9225ce..5ca974c93bd4 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1104,6 +1104,8 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
if (!vcpu_has_sve(vcpu))
val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);
+ } else if (id == SYS_ID_AA64PFR1_EL1) {
+ val &= ~(0xfUL << ID_AA64PFR1_MTE_SHIFT);
} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
(0xfUL << ID_AA64ISAR1_API_SHIFT) |
@@ -1519,6 +1521,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
{ SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },
+ { SYS_DESC(SYS_RGSR_EL1), trap_raz_wi, reset_unknown, RGSR_EL1 },
+ { SYS_DESC(SYS_GCR_EL1), trap_raz_wi, reset_unknown, GCR_EL1 },
{ SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
@@ -1543,6 +1547,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_ERXMISC0_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXMISC1_EL1), trap_raz_wi },
+ { SYS_DESC(SYS_TFSR_EL1), trap_raz_wi, reset_unknown, TFSR_EL1 },
+ { SYS_DESC(SYS_TFSRE0_EL1), trap_raz_wi, reset_unknown, TFSRE0_EL1 },
+
{ SYS_DESC(SYS_FAR_EL1), access_vm_reg, reset_unknown, FAR_EL1 },
{ SYS_DESC(SYS_PAR_EL1), NULL, reset_unknown, PAR_EL1 },
--
2.20.1